Kernicterus Health Dictionary

The term used to describe a group of conditions characterised by varying degrees of paralysis and originating in infancy or early childhood. In some 80 per cent of cases this takes the form of spastic paralysis (muscle sti?ness), hence the now obsolete lay description of sufferers as ‘spastics’. The incidence is believed to be around 2 or 2·5 per 1,000 of the childhood community. In the majority of cases the abnormality dates from well before birth: among the factors are some genetic malformation of the brain, a congenital defect of the brain, or some adverse e?ect on the fetal brain as by infection during pregnancy. Among the factors during birth that may be responsible is prolonged lack of oxygen such as can occur during a di?cult labour; this may be the cause in up to 15 per cent of cases. In some 10–15 per cent of cases the condition is acquired after birth, when it may be due to KERNICTERUS, infection of the brain, cerebral thrombosis or embolism, or trauma. Acute illness in infancy, such as meningitis, may result in cerebral palsy.

The disease manifests itself in many ways. It may not be ?nally diagnosed and characterised until the infant is two years old, but may be apparent much earlier – even soon after birth. The child may be spastic or ?accid, or the slow, writhing involuntary movements known as athetosis may be the predominant feature. These involuntary movements often disappear during sleep and may be controlled, or even abolished, in some cases by training the child to relax. The paralysis varies tremendously. It may involve the limbs on one side of the body (hemiplegia), both lower limbs (paraplegia), or all four limbs (DIPLEGIA and QUADRIPLEGIA). Learning disability (with an IQ under 70) is present in around 75 per cent of all children but children with diplegia or athetoid symptoms may have normal or even high intelligence. Associated problems may include hearing or visual disability, behavioural problems and epilepsy.

The outlook for life is good, only the more severely affected cases dying in infancy. Although there is no cure, much can be done to help these disabled children, particularly if the condition is detected at an early stage. Assistance is available from NHS developmental and assessment clinics, supervised by community paediatricians and involving a team approach from experts in education, physiotherapy, occupational therapy and speech training. In this way many of these handicapped children reach adulthood able to lead near-normal lives. Much help in dealing with these children can be obtained from SCOPE (formerly the Spastics Society), and Advice Service Capability Scotland (ASCS).... cerebral palsy

Excessive haemolysis (destruction of red blood cells) in the fetus and newborn by antibodies produced by the mother. Haemolytic disease of the newborn is most often caused by Rhesus incompatibility. This occurs when a mother with Rh-negative type blood, who has previously been exposed to Rh-positive blood through birth, miscarriage, abortion, or amniocentesis, is pregnant with a baby that has Rh-positive blood. Haemolytic disease has become uncommon since the introduction of routine preventative treatment for Rh-negative women during pregnancy (see anti-D (Rh) immunoglobulin).

In mild cases of haemolytic disease, the newborn baby becomes slightly jaundiced during the first 24 hours of life (due to excess bilirubin in the blood) and slightly anaemic. In more severe cases, the level of bilirubin in the blood may increase to a dangerous level, causing a risk of kernicterus (a type of brain damage). Severely affected babies have marked anaemia while still in the uterus. They become swollen (hydrops fetalis) and are often stillborn.

In mild cases, no treatment is necessary. In other cases, the aim is to deliver the baby before the anaemia becomes severe, usually by induction of labour at 35–39 weeks’ gestation. If the baby is too young to be delivered safely, fetal blood transfusions may be necessary. After birth, phototherapy (light treatment that converts bilirubin in the skin into a water-soluble form that is more easily excreted from the body) can help to reduce jaundice. An exchange blood transfusion may be needed.... haemolytic disease of the newborn

This is a complex part of the nervous system, extending from the cortex to the medulla in the BRAIN, from which emerge descending spinal pathways which in?uence voluntary motor activity throughout the body. Although the normal functions of the system are poorly understood, there are characteristic signs of an extrapyramidal LESION. These include disturbance of voluntary movements, notably slowness and ‘poverty’ of movement; disturbance of muscular tone, which may be increased or decreased; and involuntary movements, such as a tremor, irregular jerking movements, or slow writhing movements.

Diseases There are several diseases that result from lesions to the extrapyramidal system, of which the most common is PARKINSONISM. Others include WILSON’S DISEASE, KERNICTERUS, CHOREA and ATHETOSIS.... extrapyramidal system

Degeneration or death of nerve cells and tracts within the brain that may be localized to a particular area of the brain or diffuse. Diffuse damage most commonly results from prolonged cerebral hypoxia (which may occur in a baby during a difficult birth), cardiac arrest, respiratory arrest, or causes such as poisoning or status epilepticus (prolonged convulsions). The damage may also occur gradually due to environmental pollutants such as lead or mercury compounds (see Minamata disease) or if nerve-cell poisons build up in the brain, as in untreated phenylketonuria. Other possible causes include brain infections such as encephalitis.

Localized brain damage may occur as a result of a head injury, stroke, brain tumour, or brain abscess. At birth, a raised blood level of bilirubin (in haemolytic disease of the newborn) causes local damage to the basal ganglia deep within the brain. This leads to a condition called kernicterus. Brain damage that occurs before, during, or after birth may result in cerebral palsy.

Damage to the brain may result in disabilities such as learning difficulties or disturbances of movement or speech.

Nerve cells and tracts in the brain and spinal cord cannot repair themselves once they have been damaged, but some return of function may be possible.... brain damage

Yellowing of the skin and whites of the eyes in newborn babies, due to accumulation of bilirubin in the blood. It usually results from the liver being immature and unable to excrete bilirubin efficiently. This form of jaundice is usually harmless and disappears within a week. Rarely, severe or persistent neonatal jaundice is caused by haemolytic disease of the newborn, G6PD deficiency, hepatitis, hypothyroidism, biliary atresia, or infection.

Jaundiced babies usually require extra fluids and may be treated with phototherapy.

Exchange transfusion (see blood transfusion) may be needed in severe cases.

If severe neonatal jaundice is not treated promptly, kernicterus may occur.... jaundice, neonatal